The synthesis, crystal structure and charge distribution of pyridine perrhenate acid (C 5H 5N·HReO 4) and pyrrolidine perrhenate acid (C 4H 9N·HReO 4)

Abstract

The title compounds were synthesized and characterized by single crystal X-ray diffraction. C 5H 5N·HReO 4 is monoclinic, belonging to the space group P2 1, with a=0.5577(1) nm, b=1.2446(1) nm, c=0.5574(1) nm, β=98.07(1)°, V=0.38307(1) nm 3, Z=4, R f=0.042 and R w=0.046. Pyridine makes up for the tunnel packing with perrhenate, along the 2 1 axis of b direction. There is no inter or intra-molecular N⋯H hydrogen bond contact, but the H⋯O hydrogen bonds possibly exist intra-molecularly (H2⋯O3, 0.2984 nm; H2⋯O4, H3⋯O3 0.2917 nm;). C 4H 9N·HReO 4 is monoclinic, belonging to the space group P2 1/ c, with a=0.5504(1) nm, b=0.8876(1) nm, c=1.6222(1) nm, β=96.14(1)°, V=0.78795(1) nm 3, Z=4, R f=0.076 and R w=0.078. Pyrrolidine and perrhenate constitute a layer structure. There is an intermolecular N⋯H hydrogen bond contact (O1⋯N1 (1− x, y−1/2, 3/2− z), 0.2796 nm; N1⋯O3 (1+ x, 1/2− y, 1/2+ z), 0.2794 nm) and the H⋯O hydrogen bonds possibly exist intra-molecularly also (H3B⋯O4, 0.2983 nm; H2B⋯O4, 0.2952 nm). The charge distributions of these two compounds were calculated by CNDO/2 method. The bonding energies of C 4H 9N·HReO 4 and C 5H 5N·HReO 4 are −7.033300 and −1.937900 a.u., respectively.